It’s become a famous line: Former Sony Music chairman Gary Overton caused an uproar in Nashville this year when he declared “If you’re not on country radio, you don’t exist.” After the CMAs, that statement seems especially amusing.

It’s commonly accepted that the best way to build a sustainable mainstream country music career is if you can hit it big on country radio. But that idea has become fraught as complications are exposed: For example, the extraordinarily tough time that female artists face getting airplay. Or the fact ...